It is narrated from ‘Ubadah bin Samit (may Allah be pleased with him) that the Messenger of Allah (ﷺ) said: “Gold for gold, silver for silver, grain for grain, barley for barley, and salt for salt—equal for equal, specified for specified, and do not sell cash for anything but cash. But sell gold for silver, silver for gold, wheat for barley, barley for wheat, dates for salt, and salt for dates as you wish, hand to hand.” He said: “One of Muslim bin Yasar and the other man reduced the dates or the salt.” Abu al-‘Abbas said: In my book it is ‘from Ayyub from Ibn Sirin’, then I saw in the book of the shaykh, that is, Rabi’.
Hadith Referenceمسند الإمام الشافعي / كتاب البيوع / 1394